Ordinal numbers are adjectives, and therefore have forms for each of the three genders in German. The forms are derived from the feminine form (as introduced in the beginning of Lesson 3) by adding an 'r' (masculine) or an 's' (neuter). Thus: erste (feminine), erster (masculine), and erstes (neuter). Examples:

As in English, there are a number of idiomatic phrases associated with giving or telling time. For example, note that the half hour is given as approaching the next hour. The German preposition, um, is used to mean "at" a given time.

Es ist halb elf.

It is half past ten (10:30).

Er kommt um sieben Uhr.

He is coming at seven o'clock.

Sie kommt immer ungefähr um acht Uhr.

She always comes around eight o'clock.

Wir essen gegen sieben Uhr.

We eat about seven o'clock.

Sie gehen nach Hause auf eine Stunde.

They go home for an hour.

Es ist viertel zehn1

It is a quarter past nine

1This idiom (Es ist viertel zehn) is used especially in the southern parts of Germany, but is becoming popular among young Germans throughout the Country.

The first sentence in Gespräch 3-3 uses Beim Ballspielen in the sense of "during the ball game" or "while playing ball". Beim is a contraction of bei dem or "at the". However, das Ballspiel is a noun that represents an action ("playing with a ball"), so it is correct to use beim in the sense intended here. It is not the most beautiful way of saying this—but is correct. With the infinitive of a verb you can use beim too: Beim Spielen means "while playing". This form is more common in modern German language.

auf for (duration), after
gegen towards, about, approximately
letzt(er) last
ungefähr (at) about, approximately

Note that morgen does not change in plural; thus, Die Morgen = "the mornings". It is uncommon to use it in plural, unless as a measure of land Vier Morgen Land = "four 'morgens of land". For a plural use of "mornings", it is better to substitute die Vormittage.